It all depends on your budget and what type of viewing you plan to do with it. I'll assume you mean rear projection LCD as LCD flat panels 45" and above are going to be in the 8k to 12k range.
What I mean by "what you plan to do with it" is that plasma tvs, even though it takes a lot of viewing, do have a chance of burn in, while LCD does not. If you plan to play video games on it all day, plasma is not for you....
LCD tv's provide a better picture in really bright rooms and some models do have a better viewing angle.
Plasma screens have a glossy front screen, so glare may be a problem. Viewing angle, while good, is not as broad as some flat panel LCDs.
I'll finish later...